Drill bit nozzles

ABSTRACT

A fluid nozzle for a roller cutter drill bit wherein the nozzle has a bore, an inboard portion terminating just above adjacent parts of the cutters and an outboard portion extending downwardly substantially below the inboard portion. The outboard portion of the nozzle is adapted to form a barrier or shield between the emerging drilling fluid and the wall of the bore hole being drilled.

Umted States Patent 11 1 1111 3,744,581 Moore 1 1 July 10, 1973 [5 DRILL BIT NOZZLES 2,260,487 10/1941 Sc0tt.....; 175/340 2,749,092 6/1956 Peter..... 175/340 [75] Inventor. Roy N. Moore, Houston, Tex. 3,070,182 12/1962 Rumem 175/339 [73] Assignee; Murphy Industries, Inc 3,509,952 5/1970 Galle 175/339 Houston 3,685,601 7/1972 Hollmgshead 175/340 X Filed! Jam 28, 1972 Primary ExaminerDavid H. Brown [211 App]. No; 221,541 AttorneyC. M. Kucera [52] US. Cl. 175/340, 175/422 [57] ABSTRACT [51] Int. Cl... E211) 9/08 A nozzle for a roller cutter wherem the 58 Field of Search 175/340 339 393, nozzle has a P0rtion terminating i 175/422 above adjacent parts of the cutters and an outboard portion extending downwardly substantially below the [56] References Cited inboard portion. The outboard portion of the nozzle is adapted to form a barrier or shield between the emerg- UNTED STATES PATENTS ing drilling fluid and the wall of the bore hole being 2,900,171 8/1959 Miller et a1. 175/340 drilled. 3,137,354 6/1964 Crawford et 81.... 175/340 2,192,693 3/1940 Payne 175/340 7 Claims, 2 Drawing Figures g a w MM l DRILL BIT NOZZLES FIELD OF THE INVENTION This invention relates to nozzles and more particularly to drilling fluid nozzles for use in earth drilling bits.

BACKGROUND OF THE INVENTION A continuing problem in the drilling of bore holes in the earth is the removal of cuttings. In the drilling of earth bores, a rotary bit is connected to the lower end of a drill stern which is rotated to cause the drill bit roller cutters to roll upon the bottom of the hole to cut or crush the formation being encountered. A drilling fluid such as air, gas or mud is pumped downwardly through the drill stem and bit and rises upwardly in the annular space between the drill stem and the wall of the bore hole to the surface of the earth. One of the most important desired functions of the drilling fluid thus circulating is quickly to remove the cut or crushed particles of the formation from the bottom areas of the bore hole and from the cutters and adjacent parts of the bit to alleviate the recutting of formation chips and particles after they have been dislodged from the formation.

SUMMARY OF THE INVENTION This invention is concerned with providing nozzles for drill bits wherein the direction and circulation of drilling fluid is somewhat controlled to effect more efficient cutting removal. To this end, the nozzles are contoured so as to provide a barrier or shield between the emerging drilling fluid and the wall of the bore hole to provide a path of reduced fluid resistance to the chips circulating upwardly adjacent the bit head and the fluid nozzles.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional view, partly in elevation, of a drill bit embodying the invention, with a portion of the bit being shown rotated into the plane of the paper.

FIG. 2 is an end view of the nozzle taken along line 2-2 in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, a drill bit is shown generally at comprising a steel bit head 11 and a threaded shank 12 extending upwardly from the bit head 11 for attachment to the lower end of a drill stem (not shown). The threaded shank l2 and bit head have a chamber 13 for' the reception of drilling fluid. The bit head 11 has a plurality of downwardly extending legs l4upon which are mounted steel roller cutters l5 and 15a.

The bit head 11 may have a plurality of fluid passageways 16 which communicate with the fluid chamber 13. Within the lower end of the fluid passageway 16 is provided a nozzle 17 which serves to direct drilling fluid between the roller cutters toward the bottom of the bore hole being drilled. The wall of the passageway 16 may have an annular groove 18 therein within which is positioned an annular seal 19 to prevent leakage of fluid between the nozzle and the wall of the passage- 'I he nozzle 17 is generally of cylindrical exterior configuration and has a bore 20 extending axially therethrough. The nozzle may have an annular groove 21 in its periphery to receive the inner end of a set screw 22 whereby the nozzle may be held in operating position.

As drilling commences, the cutters l5 and 15a dislodge particles of formation from the bottom of the bore hole 23. Drilling fluid emerges from the nozzles 17 toward the bottom of the hole 23 to remove the cuttings therefrom and circulate them upwardly to the surface of the earth. The cuttings therefore must pass through the annular space 24 between the bit head and the wall of the bore hole. In so doing, some of the cuttings must pass upwardly near the fluid emerging downwardly from the nozzles 17.

In order to provide for more efficient cutting removal through these areas, the nozzle 17 has an inboard or intermediate portion 25 terminating just above adjacent parts of the cutters l5 and 15a and an outboard portion 26 extending downwardly substantially below the inboard portion 25 to fonn a barrier between the emerging drilling fluid and the wall of the bore hole. Preferably the length of the outboard portion 26 below the inner portion 25 is at least two times the dimension of the diameter of the nozzle bore 20. If desired, the nozzle 17 may be beveled as at 26a or otherwise configured to change the drilling fluid flow pattern somewhat.

When the emerging drilling fluid reaches the lower portion 25 of the nozzle, it is substantially unimpeded by the nozzle below that point and may then circulate or expand radially inwardly of the drill bit while for the length of the nozzle extension 26, the fluid is substantially prevented from moving in an outboard direction. Thus, the nozzle produces a non-circular impact pattern on and near the hole bottom to improve bottom hole cleaning of cuttings. This fluid flow pattern will also cause less interference to the upward circulation of cuttings adjacent the nozzles.

In field operations, it has been found that these nozzles provide faster drilling rates and alleviate bit cutter and bearing wear.

The foregoing disclosure and description of the in vention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spiritof the invention.

What is claimed is:

l. A rotary drill bit having a bit head,

roller cutters mounted thereon, and

drilling fluid passageways therein disposed to direct a stream of fluid downwardly between adjacent roller cutters,

a nozzle having a bore therethrough in the lower portion of said fluid passageway,

the nozzle having an inboard portion terminating adjacent the upper portions of said cutters,

the nozzle having an outer portion substantially outboard of the centerline of the nozzle bore extending downwardly substantially below the inboard portion of the nozzle to form a partial barrier between the emerging drillingfluid and the wall of the bore hole being drilled,

the bore of said nozzle being defined by said outer portion and extending along the longitudinal axis of said outer portion to continue the path of the fluid in a downward direction from said inboard portion, and

3 4 means to secure the nozzle in said drilling fluid pasa nozzle having an axial bore and an exit,

sageway. said nozzle having an inboard portion and an outer 2. A rotary drill bit according to claim 1 wherein portion with said bore terminating that said inthe length of the nozzle outer portion is at least twice board portion, but continuing along said outer porthe nozzle bore diameter. 5 tion, said outer portion constituting an axial exten- 3. A rotary drill bit according to claim 1 wherein sion of said nozzle and comprising substantially a the nozzle outer portion has beveled edges. uniform circular segment substantially parallel to 4. A rotary drill bit according to claim 1 wherein the centerline of said bore, the means to secure the nozzle in the passageway and extending beyond said nozzle exit for a distance comprises a set screw. of at least twice the diameter of the nozzle bore. 5. A rotary drill bit according to claim 1 wherein 7. A roller cutter drill bit nozzle according to claim sealing means is provided between the nozzle and the 6 wherein wall of the fluid passageway. said circular segment extends approximately 180. 6. In a roller cutter drill bit, 

1. A rotary drill bit having a bit head, roller cutters mounted thereon, and drilling fluid passageways therein disposed to direct a stream of fluid downwardly between adjacent roller cutters, a nozzle having a bore therethrough in the lower portion of said fluid passageway, the nozzle having an inboard portion terminating adjacent the upper portions of said cutters, the nozzle having an outer portion substantially outboard of the centerline of the nozzle bore extending downwardly substantially below the inboard portion of the nozzle to form a partial barrier between the emerging drilling fluid and the wall of the bore hole being drilled, the bore of said nozzle being defined by said outer portion and extending along the longitudinal axis of said outer portion to continue the path of the fluid in a downward direction from said inboard portion, and means to secure the nozzle in said drilling fluid passageway.
 2. A rotary drill bit according to claim 1 wherein the length of the nozzle outer portion is at least twice the nozzle bore diameter.
 3. A rotary drill bit according to claim 1 wherein the nozzle outer portion has beveled edges.
 4. A rotary drill bit according to claim 1 wherein the means to secure the nozzle in the passageway comprises a set screw.
 5. A rotary drill bit according to claim 1 wherein sealing means is provided between the nozzle and the wall of the fluid passageway.
 6. In a roller cutter drill bit, a nozzle having an axial bore and an exit, said nozzle having an inboard portion and an outer portion with said bore terminating that said inboard portion, but continuing along said outer portion, said outer portion constituting an axial extension of said nozzle and comprising substantially a uniform circular segment substantially parallel to the centerline of said bore, and extending beyond said nozzle exit for a distance of at least twice the diameter of the nozzle bore.
 7. A roller cutter drill bit nozzle according to claim 6 wherein said circular segment extends approximately 180* . 